This invention relates to an electrophotographic photoreceptor, a producing method of the electrophotographic photoreceptor and an image forming method, an image forming apparatus and a processing cartridge each using the electrophotographic photoreceptor.
Recently, an organic electrophotographic photoreceptor containing an organic photoconductive substance is most widely used as an electrophotographic photoreceptor. The organic photoreceptor is more advantageous than with another photoreceptor since a photoreceptor sensitive to light within the range of visible lays to infrared lays can be easily developed, a material without environment pollution can be chosen and the photoreceptor can be produced with a low price. However the organic photoreceptor has drawbacks such that a mechanical strength thereof is low, deterioration of the surface properties and a formation of scratches on the surface are tend to be occurred when the photoreceptor is repeatedly used for making many copies or prints.
Many investigations have been carried out to satisfy the various properties such as the above-mentioned.
It has been strongly demanded to inhibit the abrasive wear of the photoreceptor caused by rubbing by a cleaning blade for improving the durability of the organic photoreceptor. As an approach to such the improvement, a technique such that a resin layer having a high mechanical strength is provided on the surface or the photoreceptor has been investigated. For example, Japanese Patent Publication Open to Public Inspection, hereinafter referred to as JP O.P.I., No. 6-118681 discloses the use of a colloidal silica-containing hardenable siloxane as the surface layer of the photoreceptor. However, problems such as formation of crack, degradation of the adhesiveness to the photosensitive layer and deterioration of the electrostatic property of the photosensitive layer are caused by the use of the resin layer only composed of silica structured by repeating three dimensional siloxane, Sixe2x80x94Oxe2x80x94Si, bonds.
An inorganic-organic hybrid polymer having both properties of an organic polymer and a cross-linked siloxane component has been proposed as a trial of improvement of adhesiveness with the photosensitive layer and the anti-wearing property of the resin layer. For example, JP O.P.I. No. 2000-221723 discloses a resin layer containing a polymer composed of a chemical combined product of polysiloxane and silyl group-containing vinyl resin. However, a photoreceptor having such the resin layer is insufficient as a photoreceptor for the most widely used electrophotographic method such as a Carlson process since the electrophotographic property is insufficient and fog and blur of image are tend to be occurred when the photoreceptor is repeatedly used even though the wearing resistively of the photoreceptor is improved.
The inventors have proposed, Japanese Patent Application No. 1-70308, a layer of a siloxane resin having an electric charge transporting property providing group and a cross-linked structure for the resin layer of the photoreceptor satisfying both of the mechanical wearing resistively and the electrophotographic property at the repeatedly using. The photoreceptor having such the resin layer is practically useful as an organic photoreceptor with a high durability since the photoreceptor is improved in the wearing resistively and the electrophotographic property such as the charging ability, photosensitivity and charge remaining property at repeatedly using which are important problems of the usual photoreceptor. However, such the resin layer is become a layer behaving as a strong elastic substance since a highly cross-linked resin peculiar to the siloxane resin is formed in such the resin layer. Therefore, the torque between the photoreceptor and a cleaning blade is increased, when a cleaning device using a cleaning blade is used, problems such as the instability of the cleaning suitability of toner and the turn over of the cleaning blade are tend to be often occurred. Moreover, is found a problem that the resolving power of image formed on the photoreceptor is considerably lowered under a high humid condition compared with usual photoreceptors.
The object of the invention is to provide a high durable electrophotographic photoreceptor improved in the resistively to the abrasive wearing caused by rubbing by a cleaning blade and the electrophotographic properties such as the charging ability, photosensitivity and the charge remaining property, and a photoreceptor having a resin layer which is superior in the stability to the cleaning property of toner and the turn over of cleaning blade, furthermore, to provide a photoreceptor by which a sharp image can be obtained under a high humid condition. Further object of the invention is to provide a producing method of the photoreceptor, an image forming method, an image forming apparatus and a processing cartridge each using the photoreceptor.
The invention is described.
The photoreceptor of the invention comprises a support and, provided thereon, a photosensitive layer and a resin layer wherein the resin of the resin layer comprises an organic polymer component, siloxane component and charge transportable component.
The resin preferably composed of organic polymer skeleton (main chain) and the siloxane component and charge transportable component at side chain of the skeleton.
The organic polymer may comprise an anti-oxidant component, preferably at side chain of the skeleton.
The organic polymer may have an epoxy group or an open ring group thereof, preferably at the chain of the skeleton, more preferably in the siloxane component.
The organic polymer may have a fluorine atom, which may be incorporated in the polymer skeleton or at the side chain thereof.